Aerodynamic deflector

ABSTRACT

An aerodynamic body for disposition on the roof of an automobile is disclosed. The body is essentially wedge shaped with side skirts and having a curved rising surface for causing the wind to flow over and around a trailer being pulled by the automobile to thereby reduce the wind drag on the trailer and improve trailer tracking during travel.

I Unlted States Patent 11 1 1111 3,731,969 Bildfell 1 May 8, 1973 54]AERODYNAMIC DEFLECTOR 2,036,560 4/1936 Backus ..296/1 s 3,484,130 121969 R d ....296 l S [75] Inventor khan 2,122,422 7/1938 11:1 ...105 2 ACanada 3,241,876 3/1966 Saunders..... ....296/1 S 3,309,131 3/1967Saunders..... ....296/1 S [73] Asslgnee' 3,415,566 12/1968 Kerrigan..296/1 5 [22] Filed: May 12, 1971 Primary Examiner-Leo Friaglia [2!]Appl' 142467 Assistant Examiner-John A. Pekar AttorneyPhilip T. Mitches[30] Forei n A lication Prior-it Data 3 pp y [57] ABSTRACT Nov. 16,1970Canada ..O98171 I An aerodynamic body for disposition on the roof of anautomobile is disclosed. The body is essentially wedge CCll ..296/1138622183583 Shaped with side skirts and having a curved rising Sul 58F .ld "296 l S 9!. face for causing the wind to flow Over and around ale 0 care trailer being pulled by the automobile to thereby 105/2 Areduce the wind drag on the trailer and improve trailer [56] ReferencesCited tracking during travel.

UNITED STATES PATENTS 10 Claims, 8 Drawing Figures 3,348,873 10/1967Saunders ..296/] S PATENTED 8 I975 SHEET 2 OF 3 FIG 3 If mil/luff,

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PATENTEU HAY 8 I973 sum 3 OF 3 AERODYNAMIC DEFLECTOR The inventionrelates to devices for deflecting air streams striking moving vehicles,particularly devices for deflecting, from a trailing vehicle and thelike, air streams caused by the wind or forward movement of a firstprime mover vehicle moving ahead and in front of said trailing vehicle.

By way of introduction, when a first vehicle such as an automobiletravles at average to high speeds on a highway, road and the like, andpulls a trailing vehicle, such as a caravan, mobile home, housetrailer,wagon or the like high wind resistence, wind drag, imposed upon thetrailing vehicle because of the medium to high speed of travel thereof,usually causes the trailing vehicle to sway from side to side. Duringsuch action, sympathetic vibrations may be induced causing more. violentreciprocal swaying than tolerable or even desirable.

The invention achieves a reduction of wind drag forces on a trailingvehicle and hence the reduction of to and fro instability of a trailingvehicle when pulled by a first advancing vehicle. Particularly, theinvention achieves an aerodynamic deflecting device disposed apredetermined distance from the trailing vehicle such that wind isdeflected by the deflector around as well as up and over the trailingvehicle to thereby reduce wind drag and to and fro action on thetrailing vehicle caused by severe wind resistence.

Although the aerodynamic body (deflector) can be used with beneficialresults with any size trailing vehicle which is pulled by a poweredvehicle (prime mover vehicle), the aerodynamic body is particularlybeneficial when the height of the caravan is greater than the height ofthe prime mover vehicle, particularly by about one and one-half theheight of the prime mover vehicle. I I

The invention therefore contemplates an aerodynamic body for mounting onthe top of a prime mover vehicle when pulling a trailing vehiclecomprising a deflection member having an aerodynamic striking surface,an upper portion and a lower portion thereof, the lower portion thereofconnected to a lead ing edge member, said body having means thereon forconnecting the same, in near proximity, to the top of the prime movervehicle, such that the leading edge is adapted to be disposed at rightangles to the angle incidence of the prime mover vehicle, the upperportion disposed a predetermined distance from the top and down streamfrom the leading edge such that the deflector member disposes theaerodynamic surface, in one plane, at right angles to the angle of theattack causing wind to strike the surface and deflect it upward and awayfrom the prime mover vehicle.

The invention will now be described by way of example, reference beinghad to the accompanying drawings in which;

FIG. 1 is a side view of an embodiment of the aerodynamic body whenmounted on the top of an automobile pulling a trailer.

FIG. 2 is the front view of the embodiment of FIG. 1.

FIG. 3 is the plan view of FIG. 1. I

FIG. 4 is a plan view of the aerodynamic body of FIG. 1.

FIG. 5 is a section along lines 55 of FIG. 4.

FIG. 6 is a section along lines 6--6 of FIG. 4.

FIG. 7 is a perspective of an embodiment of the aerodynamic body mountedon the roof.

FIG. 8 is an elevation of tying mounting member with inserted top viewof a threaded securing plate used to secure the aerodynamic body to theroof.

Referring to FIG. 1 an automobile (prime mover vehicle 20), having aroof 21 with a rear roof portion 22 pulls a trailer (trailing vehicle)23 behind it. The trailer 23 is connected by appropriate means 24 to thestern of the automobile 20.

A wind deflecting aerodynamic body 26 is mounted on the roof 21,although it is preferred to mount the body 26 on the rear roof portion22. The aerodynamic body 26 comprises a thin and narrow leading edgemember 27 with a mid portion 28 and two extremities 29 and has a concavecurved aerodynamic surface 31, the expanse of which disposes a narrowlower portion 32 communicating with the mid portion 28 and a wider upperportion 33 disposed above and to the rear of the leading edge member 27in order to display an aerodynamic scoop like body which rises fromfront to rear. From opposite edges of the concave curved aerodynamicsurface 31, between the narrow lower portion 32 and the upper widerportion 33, are depended opposite wedge shaped skirt members 39 withapex thereof at the point of union among the mid portion 28, extremities29, and curved aerodynamic surface 31. The mirror wedge shaped skirtmembers 39 are straight and have the respective surfaces disposed atright angles to the curved aerodynamic surface. Nevertheless, it wouldappear that satisfactory results of the aerodynamic body 26 could beachieved if the skirt members 39 traced out a locus of points of aslight concave curve.

To the under side of the leading edge member 27 and to the underside ofthe aerodynamic surface 31 are ,mounted a plurality of mounting members34 such as suction cups 36 and suction cups with extension stems 37 forsecuring the areodynamic body 26 to the roof 21. Retaining straps 38,which frictionally engage the underside of longitudinally running roofgutters 40, may also be used to constrain the aerodynamic body 28 on theroof 21. The retaining straps 38 and the suction cups 36 may be usedindependently or co-operatively. In most applications it has been foundnecessary to use them co-operatively because of the magnitude of thewind drag on the aerodynamic body 26, although this may be avoided bythe use of tying mounting members 34 (FIG. 8).

Tying mounting members 34 include a round head bolt portion 41 adaptedto pass through an orifice 42 in the extremity 29 and thence screw intoa threaded securing plate 43 secured as by rivets 44 onto the uppersurface of the roof 21. In this way the leading edge member 28 s rigidlysecured to the roof 2].

Referring again to the aerodynamic body 26, it is preferred that theleading edge member 27 and the concave aerodynamic surface 31 be flatand be at right angles across the line of travel of the automobile 20and trailer 23 and displaying and increasing angle of attack from narrowlower portion 32 to wider upper portion 6 33. In this configurationmaximum wind displacement trailing vehicle 23 as well as about and alongthe sides of the trailing vehicle. In such configuration it is preferredthat the leading edge member 27 is held in close proximity to the roof22 for example within two inches thereof.

More particularly, the aerodynamic surface 31 preferably is a locus ofpoints along an arc resembling a sheet conic such as a flat sheetparabola. The vertex of the parabola is coincident with the intersectionof the narrow portion 32 and the leading edge member 27 and the axis ofthe parabola is disposed perpendicular to the line of travel of theautomobile 20. Such parabolic sheet profile of the aerodynamic surface31 ensures adequate aerodynamic properties without the requirement thatthe aerodynamic body 26 be of such large size to be physicallycumbersome and heavy.

The areodynamic body 26 preferably has the following dimensions.

Length of leading edge member 27, 53 inches.

Thickness of leading edge member 27, 1 inch.

Cord length of aerodynamic curved surface (from upper portion 50 tolower portion 32) 32 inches.

Width of narrow lower portion 32, 28 inches.

Width of upper wider portion 33, 50 inches.

Width of skirt members 39, from 2 inches at apex to 7 inches at theupper wider portion 33. Rise of the upper portion 33 above the lowerportion 32, 15 inches.

Although the embodiments of the invention have been disclosed asincluding a curved aerodynamic surface 3], nevertheless such surfacecould bea flat inclined plane which could be disposed along the core 31'of the surface 31 (see FIG. It should be emphasized that the position ofthe aerodynamic body on the roof of the automobile is not too criticalalthough by trial and error one will discover the ideal position of theaerodynamic body 26 on the roof in relation to the height of thetrailing vehicle 23 proposed to be pulled.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. An aerodynamic body for mounting on the top of a prime mover vehiclewhen pulling a trailing vehicle wherein a thrust is exerted on theaerodynamic body by virtue of the wind resistance of the moving primemover vehicle while it proceeds along its line of travel, said bodyhaving an (effective) angle of attack inclined in relation to the primemover vehicle and comprising a deflection member having an aerodynamicstriking surface generally curved upward and rearwardly from a lowerfront portion to an upward rearward portion, the lower portionconnecting to a surface of a leading edge member having one side thereofperpendicular to the line of travel and means thereon for disposing thebody in near proximity and above the top of the prime mover vehicle suchthat wind striking the surface is deflected, in the lower portions,upward and outward away from the top of the prime mover vehicle andhence over the trailing vehicle.

2. The body of claim 1 wherein the upper portion has width which istwice the width of the lower portion.

3. The body of claim 2 wherein the aerodynamic surface (is a flatinclined plane) approaches that of a i fhe body of claim 2 wherein theaerodynamic surface is a concave sheet curve.

5. The body of claim 2 wherein the aerodynamic surface disposes fromlower portion toupper portion an increasing angle of attack.

6. The body of claim 5 wherein the curve is one arm of a sheet parabolawith vertex located at the leading edge.

7. The body of claim 5 wherein means for connecting the body to the roofincludes retaining straps secured to the extremities of the leading edgemember and adapted for connection to the prime mover vehicle.

8. The body of claim 7 further comprising skirt members depended fromopposite edges of the aerodynamic surface between the lower narrowportion and the upper wider portion, said skirt members adapted fordiverting wind about the trailing vehicle.

9. The body of claim 2 wherein means for connecting the body to the roofincludes retaining straps secured to the extremities of the leading edgemember and adapted for connection to the prime mover vehicle.

10. The body of claim 21 wherein the upper portion rises above the lowerportion by about one-half the width of the lower portion.

1. An aerodynamic body for mounting on the top of a prime mover vehiclewhen pulling a trailing vehicle wherein a thrust is exerted on theaerodynamic body by virtue of the wind resistance of the moving primemover vehicle while it proceeds along its line of travel, said bodyhaving an (effective) angle of attack inclined in relation to the primemover vehicle and comprising a deflection member having an aerodynamicstriking surface generally curved upward and rearwardly from a lowerfront portion to an upward rearward portion, the lower portionconnecting to a surface of a leading edge member having one side thereofperpendicular to the line of travel and means thereon for disposing thebody in near proximity and above the top of the prime mover vehicle suchthat wind striking the surface is deflected, in the lower portions,upward and outward away from the top of the prime mover vehicle andhence over the trailing vehicle.
 2. The body of claim 1 wherein theupper portion has width which is twice the width of the lower portion.3. The body of claim 2 wherein the aerodynamic surface (is a flatinclined plane) approaches that of a plane.
 4. The body of claim 2wherein the aerodynamic surface is a concave sheet curve.
 5. The body ofclaim 2 wherein the aerodynamic surface disposes from lower portion toupper portion an increasing angle of attack.
 6. The body of claim 5wherein the curve is one arm of a sheet parabola with vertex located atthe leading edge.
 7. The body of claim 5 wherein means for connectingthe body to the roof includes retaining straps secured to theextremities of the leading edge member and adapted for connection to theprime mover vehicle.
 8. The body of claim 7 further comprising skirtmembers depended from opposite edges of the aerodynamic surface betweenthe lower narrow portion and the upper wider portion, said skirt membersadapted for diverting wind about the trailing vehicle.
 9. The body ofclaim 2 wherein means for connecting the body to the roof includesretaining straps secured to the extremities of the leading edge memberand adapted for connection to the prime mover vehicle.
 10. The body ofclaim 21 wherein the upper portion rises above the lower portion byabout one-half the width of the lower portion.